Process and apparatus for desiccating fluid substances.



R. W. G. STUTZKE.

PROCESS AND APPARATUS FOR DESICCATING FLUiD SUBSTANCES.

APPLICATION FILED [150.28, 1915.

1,215,889, Patented Feb. 13,1917.

i an srarns ATN onion.

Brennan w. o. sru'rzxn, or cnrcneo, ILnInoIs, nssrcn'oia, BY MESNEASSIGNMENTS,

ro e. ARTHUR BUTHL, or CHICAGO, ILLmoIs.

PROCESS AlITD APPQRATUS- FOR DESICCATING FLUID SUBSTANCES.

Specification of Letters Patent.

Patented net. is, roar.

Application filed. December 28, 1915. Serial No. 69,075.

To all whom it may concern:

Be it known that I, RICHARD W. G. STUTZKE, a subject of the Emperor ofGermany, residing at Chicago, in the'county of Cook and State ofIllinois, have invented a .new and useful Improvement in Processes stoodfrom the following detailed specification which is descriptive thereofand from the drawings accompanyingand forming a part. of the same.

In this drawing, Figure 1 is a diagrammatic vertical sectional view,partly in elevation, of a simple form of desiccating apparatusconstructed in accordance with my invention, and Fig. 2 is a top planview of thesame. I

It may be said by way of introduction that my process of desiccationinvolves the continuous use of the same desiccating medium, this mediumbeing circulated and recirculated through a practically-closed system ofconduits, nothing entering the system save the solution which is to bedesiccated, and nothing leaving it save the desiccated product and themoisture removed therefrom. The only energy used in the process (asidefrom radiation and leakage losses) therefore is that relatively smallamount required to continuously circulate the medium, together withthose heat units actually required to evaporate the moisture from theproduct to be desiccated at the working pressure. v

The desiccating chamber of my apparatus is in the form of a cyclone dustcollector,

designated by the numeral 10 in the drawings and having theusualtangential inlet "211at its-upper cylindrical portion and a 50.

depending outlet pipe 12 having openings in its lower end and arrangedaxially withinwthedesiccation chamber-a The outlet 12'communicateswith-a conduit 13 leading to the inlet side-of acirculating pump which, as shown in thei dra ngs, is of the conventionalcentrifugal type and designated .by 14. From the tangential outlet ofthis centrifugal circulating punip an outlet conduit 15 leads to aheating chamber 16 which may be heated as by meansof the pipe coil 17,The heating chamber 16 opens directly into the cyclone inlet 11. Thelower end of the cyclone collector has the ordinary conical formationand is provided at the bottom with a four-armed dumping gate 19. Aloaded outlet valve 20 which may be set at any desired pressureislocated in a convenient position along the length of the outletconduit 13, and may discharge into a pipe 21 which may vent directly tothe atmosphere or to another collector as will later appear.

The operation of the apparatus above de- I scribed is as follows:

The escape valve 20 will be set for a certain predetermined pressure,for instance, one fourth of an atmosphere, a suitable heating fluid willbe admitted to the c011 l7, and the circulating pump 14'w1ll be drivento cause the air within the apparatus to circulate therethrough in thedirection shown by the arrow in the drawing. When suflicient time hasbeen given for the entire apparatus, including the air therewithin, toreach a drying temperature of say, 250 F.. or thereabout, the fluidsubstance to be desiccated is admitted through the pipe 17 and sprayedout of the nozzles 18 into the annular chamber of the cyclone collector.

As the fluid is sprayed into the desiccation contact with theissuingjets of fluid again.

completely saturates the air within the circulating system in a veryshort t me and due to the. heating effect of the coil 17 the 'Thecontinuous evaporation of moisture moisture continues to be evaporated,causing a rise in pressure within the apparatus. When the pressure hasreached the predetermined level the valve 20 opens, and in the normaloperation of the apparatus will remain open, adjusting its opening totherate no of supply of moisture and heat within the circuit. The airwhich originally occupied the closed system is very soon entirelydisplaced by evaporated moisture or steam, and in the normal operationof the system after that time 'is reached, the desiccating medium issteam which has been superheated by the coils 17. Each cubic foot ofthis superheated steam as it enters the desiccating chamber 10 iscapable of absorbing a fixed quantity of moisture with the resultanttendency to rise in pressure, which tendency is offset by the opening ofthe valve 20. The cyclone collector will be effective to separatepractically all of the dried products from the outgoing current ofsaturated steam. If it is found that any appreciable quantity of thedried powder is escaping through the valve 20 and outlet conduit 21, thelatter may be vented into any desired form of collecting chamber for thedeposit of this powder.

The higher the pressure maintained with in the closed system, thesmaller the circulating pump 14 may be. Such higher pressures, ofcourse, inevitably entail a higher temperature for superheating thesteam within the system, and for this reason as well as because of thedifliculty in constructing a large apparatus capable of with standinghigh internal pressures, and of packing the joints and glands of suchapparatus, such high pressures will not ordinarily be resorted to,except where compactness is greatly to be desired. en using my apparatusfor desiccat- 1ng m lk, eggs, sugar solutions, and the like, I prefer tooperate under pressures only sllghtly in excess of atmospheric, it beingin fact a. great convenience to so regulate the internal pressures thatat the bottom of the cyclone collector 10, the pressure may be 'solittle above or below atmospheric that the dumping gate 19 may bedispensed with and an ordinary'aperture made use of.

While I have shown and described in considerable detail one specificembodiment of my invention, and the exact manner in which the process iscarried out in such embodiment, it is to be understood that this showingand description is illustrative only and'for the purpose of making myinvention more clear, and that I do not regard the invention as limitedto these details, nor to any of them, except in so far as I haveincludedthe same within the terms of the following claims, in which itis my intention to claim all novelty inherent in my invention as broadlyas is' possible in view of the prior art.

What I claim as new and desire to seciri'e by Letters Patent is: v

1. The process of evaporating liquids which consists in spraying theliquid into an atmosphere of its own vapor, circulating the saidatmosphere and superheating it 2. The process of evaporating liquidswhich consists in spraying the liquid into an atmosphere of its ownvapor under pressure, circulating the said atmosphere and superheatingit during its circulation, and venting the evaporated moisture from thecirculating system.

3. The process of desiccating'liquids carrying solid substances therein,which consists in spraying the said liquids into a closed chamber,maintaining a circulation from and back to the said chamber,continuously supplying heat to the circulating fluid, venting theevaporated liquids from the circulating system, and collecting thedesiccated solids.

4. The process of desiccating liquids carrying solid substances therein,which consists in spraying the said liquids into a collecting chamber,setting up a circulation from and back to the said chamber, continuouslysupplying heat to the circulating fluid, venting the evaporated liquidsfrom the circulating system at a point'removed from the said collectingchamber, and collecting ghe desiccated solids within the said cham- 5.The process of desiccating liquids carrying solid substances thereinwhich consists in spraying the said solidsinto the tangential inflowportion of a cyclone collector, setting up a circulation from the outletof the said collector back to the said tangential inlet, continuouslysupplying heat to the circulating fluid, ventlng the evaporated liquidsfrom the circulating system, and collecting the desiccated solids withinthe said cyclone collector.

6. A desiccation apparatus comprising a circulating system, means forsetting up a circulation of gases within the said system,

-means for supplying heat to the circulating medium, means for sprayinga liquid to be desiccated into the said circulating medium, and meansfor venting the said circulating system to limit the pressure therein.

7. A desiccation apparatus comprising, in combination, a collectingchamber, a circulating system for conveying fluid from the said chamberand back to the same again, means for setting up a circulation throughthe said system, means for supply ing'lheat to the said circulatingmedium, means for spraying a liquid to be desiccated into the saidcollecting chamber, and means removed from the said collecting chamberfor venting the said circulating system to limit rise of pressuretherein.

tangential inlet portion of the said collector, a circulating systemleading from the outlet of-the saidcollector back to the said'tangentialinlet, means for setting up-a circula- 5 tion throughthe said system,and means'for venting the said system to limit rise of pressure therein.7

9. A desiccation apparatus comprising, in combination, a vcyclonecollector, liquid lospray nozzles discharging into the tangential inletportion of the said collector, an outlet pipe extendmg from the centraloutlet of the said collector, a pressure relief valve in the same, acirculating pump in the said outlet pipe, an inlet pipe on the 15discharge side of thesaid circulating pump, saidinlet pipe leading tothe said tangential inlet, and a heater interposed in the length of thesaid inlet pipe.

RICHARD W. G; STUTZKE.

